Sulfurized polyolefins are known additives for lubricating oils. They have been found useful as extreme pressure (EP) agents in lubricating oils, such as gear and cutting oils.
The prior art discloses methods for preparing a sulfurized triisobutylene which has sufficiently active sulfur to satisfactorily function as an extreme pressure agent and yet remain relatively insensitive to copper, that is, have a copper strip corrosion reading (3 hours/250.degree. F.) of less than 4A. However, as reducing the total reaction time is a continuing concern (for obvious reasons of economics) and as the time concern is not answered by the prior art, work has progressed on finding how to prepare sulfurized triisobutylene in the shortest time possible.
In the instant invention it has been unexpectedly and surprisingly found that the reaction time in preparing sulfurized triisobutylene is reduced to a degree previously unobtainable when the sulfurization reaction is conducted in the presence of these halogen substituted organic promotors.